The Journal of investigative dermatology
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J. Invest. Dermatol. · Dec 2003
Case ReportsA novel loss-of-function mutation (N48K) in the PTEN gene in a Spanish patient with Cowden disease.
Cowden disease, also known as multiple hamartoma syndrome, is a rare disease inherited in an autosomal dominant pattern, which confers a high risk of developing breast and thyroid carcinomas. Mutations in PTEN, a tumor suppressor gene located on chromosome 10q23, have been identified in patients with Cowden disease. In this work, the direct sequencing of all coding regions of the PTEN gene led us to the identification of N48K, a new germline PTEN missense mutation, in a patient suffering from Cowden disease. ⋯ Moreover, by functional analysis we found that the ability of PTEN N48K mutant protein to inhibit the activation of the proto-oncogene PKB/Akt was impaired, supporting the involvement of N48K mutation in Cowden disease. Loss of heterozygosity using three microsatellites (D10S215, D10S541, and D10S564) and the complete sequence analysis of PTEN exons in breast and endometrial tumor samples from the same patient were also carried out in an attempt to identify additional PTEN somatic mutations. The lack of loss of heterozygosity or additional mutations in tumor samples suggests that abnormalities of the regulatory regions of the PTEN gene or haplo-insufficiency might occur in tumors from Cowden disease patients.
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J. Invest. Dermatol. · Dec 2003
Perceptual matching for assessment of itch; reliability and responsiveness analyzed by a rank-invariant statistical method.
The aim of this study was to evaluate the reliability and responsiveness of a new device-perceptual matching by Matcher (Cefar Medical AB, Lund, Sweden)-in the assessment of the progress of experimentally induced itch as well as determine the reliability of the method in patients with skin disease and itch. The perceptual matching unit electrically stimulates the skin of the fingers in the left hand. When the amplitude of the sensation corresponded to that of the experienced itch, the subject was instructed to halt the stimulation and a value was automatically saved in the electronic device. ⋯ The augmented rank order coefficient was high (0.98). In conclusion, Matcher measures itch intensity via perceptual matching with a high reliability and excellent responsiveness. The method is stable and can be recommended as an assessment tool for itch intensity both in experimental conditions as well as in patients with skin disease and itch.